The preparation of vinyl halide-containing polymers by suspension polymerization of vinyl halide either alone or in combination with other monomers is well-known. Briefly, the process comprises adding water, the monomer, initiator and suspending agent to the reaction vessel which is jacketed. The reaction mass is heated by injecting steam into the reaction vessel. Once at desired temperature the reaction is maintained at a predetermined temperature by controlling the temperature of the water in the jacket. The reaction is allowed to proceed until it reaches a predetermined conversion level. In some instances the polymerization is terminated by the addition of a material known as a chain-stopping agent. Upon reaching the desired conversion level, the pressure is released by venting usually to a compressor. This pressure release is often called stripping since it reduces the amount of unreacted monomer. The resulting product is a slurry of vinyl halide-containing polymer in water, which contains also unreacted vinyl halide.
More recently, attention has been directed to the problem of preparing polyvinyl halide-containing polymers which contain only a minor amount, if any, of unreacted vinyl halide. My invention is directed to this problem.